Wheel for swimming pool vacuum cleaner head



Oct. 22, 1968 E. E. PRESBY ETAL. 34@6416 WHEEL FOR SWIMMING POOL VACUUM CLEANER HEAD Filed May 5, 1967 may} 1 w & 5 w 1 a K fi am 7 7 Mm M fi m un t d at S Patent" ABSTRACT OF THE DISCLOSURE p For a swimming .pool vacuumcleaner head, a noncorrosive, self-lubricating support wheel composed of a polymeric resin rotatably mounted on a polymeric resin axle. The axle is recessed to engage the cleaner head-and is held to ,the head in axial tension by'a screw engaged axially of theaxle. 3

Background of the invention Vacuum cleaners for cleaning debris from the bottom of a swimming pool have long been used. Generally, these vacuum cleaners include a head provided with wheels and to which is connected the intake of a water circulation pump provided for the pool. The head is guided along the pool bottom and, as water flows into the head, debris is collected from the pool bottom; such debris is removed from thewa'ter by a filter before the water is returned to the pool. The supporting wheels mounted on the head present a problem which this invention overcomes.

In the past, the wheels for pool cleaner heads have been constructed of'rubber tires bonded to cylindrical brass sleevesj They' were mounted to the head by securing a threaded shaft in and between a pair of slots in the body of the head. A brassbushing was loosely disposed about the intermediate portion of the threaded shaft, and within the sleeve to which the tire is bonded, to reduce friction while the wheel rotated. Conventional nuts were used to secure the shaft to the body of the head. r

The rubber wheels have proved unsatisfactory because the pool water usually contains a number of chemical additives which tend to attack and corrode natural aswell as synthetic rubber. These same additives also corrode the brass bushing and sleeve thereby increasing the friction present between the sleeve and the bushing and, in time, preventing the wheel from rotating.

Considering the purpose of the wheels and their use, the construction described above has proved relatively expensive. Also, inordinate attention is required to maintain the heads properly serviceable.

Summary of the invention This invention provides a simple, inexpensive, low-friction, and non-corroding wheel construction for a swimming pool vacuum cleaner head. The head is adapted to be connected to a duct extending from the intake of a pool circulation pump and defines an inlet opening to the duct. The head defines multiple pairs of aligned, essentially vertical slots which receive notched axles upon which wheels are mounted. The wheels and their axles are constructed of readily available and inexpensive polymeric resin which is resistive to the chemical additives found in swimming pools; the resins are lubricated by water. Briefly, the invention provides a wheel mounted on an axle which is disposed within the aligned pairs of vertical slots, and wherein the diameter of the axle is greater than the width of the corresponding slot.

The axle comprises a cylindrical member defining, adjacent each opposite end thereof, a pair of opposed notches. One pair of notches is spaced inwardly from one end of the axle. The other pair of notches open to the I 3,406,416 Patented Oct. 22, 1968 other end of the axle. The length of the axle from notch side wall surfaces closest to the one end of the axle to the other end of the axle is less than the'distance between the exterior surfaces of the slotted walls of the cleaner head. Means are provided for mounting the axle to the head so that the axle notches are engaged in the slots. The notch side walls adjacent the one end of the axle thereby abut the adjacent exterior slotted wallsurface. A support wheel is rotatably mounted on the axle between the pairs of notches whereby the vacuum cleaner'head is supported by the wheel and can be guided along the bottornofthe swimming pool. Brief description of the drawings 7 FIG. 1 is a plan view of the swimming pool vacuum cleaner head constructed according to this invention;

FIG. 2 is an enlarged'front elevationalsection view taken along lines 22 of FIG. 1; and

FIG. 3 is a plan view of an axle.

. Description of the preferred embodiments Referring to FIG. 1, a vacuum cleaner head 6 includes a port 8 for connecting the head to a suction line (not shown). The head also includes a connecting member 10 secured to the .port by a bolt 12; a suitable elongate handle is connected to the head via member 10. The head is supported above the pool floor by a plurality of wheels 14 arranged in a triangular array relative to each other.

The head includes a substantially C-shaped body 16 having a horizontal major surface 18 and, transverse thereto, depending peripheral side walls 20. The head also forms rectangular, upwardly extending, downwardly open, hollow housings 22, the opposite walls of which define aligned vertical slots 24 (see FIG. 2) for receiving an axle shaft 26 for a corresponding one of wheels 14, as shown in FIG. 2.

As seen in FIGS. 2 and 3, each axle 26 is provided with diametrically opposed pairs of notches 28 and 30 adjacent the opposite ends of the axle shaft. The notches have -base surfaces 31 aligned parallel to eachother and spaced apart a distance slightly less than the width of slots 24 through V the opposite walls of each of housings 22. Also, each notch 30 has side walls 33 spaced apart a distance greater than the thickness of the housing walls through which slots 24 are formed. Notches 28 open to the end of the axle shaft, and thus have only one wall 33 apiece. Between the notches, the exterior of the axle is circularly cylindrical and has a diameter greater than the width of slots 24. To strengthen the axle, the intersections between notch surfaces 31 and 33 are radiused as at 34. The end of the axle adjacent notch 28 includes a coaxial threaded hole 35 to receive a threaded bolt or machine screw 40 for securing the axle to the body 16.

The wheels comprise a tire-like wheel body 36 and a central liner sleeve 38 to which the wheel body is circumferentially secured. The axial length of each sleeve 38, and the axial thickness of each wheel body is substantially equal to the axial length of the central cylindrical portion of each axle, and is less than the distance between the opposing surfaces of the walls of housings 22 through which slots 24 are formed. The inner diameter of each sleeve 38 is slightly larger than the outer diameter of the axle central cylindrical portion.

To mount each wheel to the body, the wheel is slipped over axle 26 so that it is rotatably supported on the axle. The axle then is inserted into a desired one of housings 22 by aligning notches 28 and 30 with slots 24 in the side walls of the nozzle. A machine screw 40, for example, is then inserted through a large diameter washer 41 and-is threaded into threaded hole 35 in the axle. With the washer disposed between the screw head and the adjacent outer surface of the wheel housing the 3 t: i' screw is tightened until the washer engages the outer surface ofhousing 22 and those ones of wall,33 of notches 30 which are farthest from the screw engage the other outer slotted surface of the housing. The axle is thus held'in tension within the housing. The wheel is free to' rotate on the axlewit-hin its housing.

In view of the foregoing and as shown in FIG. 2, the length of the axle between right walls 33 of notches 30 and the end of the axle to which notches 28 open is .less than the distance between the opposite slotted exterior surfaces of the housing.

If, after extended use, the periphery of the wheel becomes Worn andits diameter decreased, it is readily adjusted by loosening the machine screw and sliding the axle and the wheel downwardly relative to its housing until the wheel extends the desired distance beyond the underside of the housing side walls. I

In its preferred construction, the axle is constructed ,of a thermoplastic polycarbonate resin sold under the trademark -Norel, by General Electric Company. This resin combines high tensile strength with a low coefiicient of friction, and at the same time fully resists all chemicals that are customarily found, inswimming pool waters. Wheel body 36 preferably is constructed of a polyurethane resin sold under the trademark Texin by the Mobay Chemical Company. Alternatively, high density polyethylene can be used to advantage in fabricating the wheel body. Liner sleeve 38 preferably is constructed of Celcon, an acetal resin derived by polymerization of formaldehyde and manufactured by the Celanese Corporation; a bond between this resin and polycarbonate resins is readily obtained. To construct the liner of Celcon acetal resin is especially advantageous because of the low coefiicient of friction betwen this resin and Norel polycarbonate resin in the presence of water. Celcon and Texin resins are inert to the chemicals present in the pool water.

Preferably, the liner 38 and the axle 26 fit loosely to permit water to enter the space between them. This further reduces friction when the vacuum cleaner head is guided along the bottom of the pool and enhances the ease with which the pool bottom is cleaned.

We claim:

1. In a vacuum cleaner head for use in swimming pools and the like and defining a plurality of hollow, downwardly open support wheel housings each having opposite side walls, the side walls of each housing defining a pair of aligned substantially vertical slots extending to and opening to the underside of the head, a wheel 'axl'e engaged with each pair'of slots'and spanning each housing, and a head supportingwheel rotatably mounted on the axle in the housing, the improvement in the wheels and their axles wherein, as to each housing, the

axle comprises an elongate circularly cylindrical member defining adjacent each opposite end thereof a pair of diametrically opposed notches. extending normal to the length of the axle, thediarneter' of the axle exclusive of the notches -being greater than the width of said' slot s,

being spaced inwardly from the oneendand'liaving side wall surfaces spaced apart axially offthe a'xle'a distance greater than the thickness of the housing portion side walls, the other pair of notches opening to the other end of the axle, the notches ,having;base surfaces spaced apart diametrically of the axle'a distance less than the width of said slots, the'length of theaxle between those notch side wall surfaces proximate the one'end of the axle and'the other end of the axle being less than the distance between the exterior surfaces of the slotted housing walls, means for mounting the axle to" the headso thatth'e'axle notches are engaged in said slots and the'axle traverses the hollow interior of thehousing and so that said notch side walls are abutted against the adjacent exterior housing side wall surface, the support wheel'b'eing rotatably mounted on the axle between the pairs of notches. a

2. Apparatus according to claim 1 wherein each axle is fabricated of polycarbonate resin. i

3. Apparatus according to claim 2 wherein each wheel is fabricated of polyurethane resin.

4. Apparatus according to claim 3 including a sleeve disposed about the axle for rotation thereabout and to which the wheel is secured circumferentially.

5. Apparatus accordingto claim 4 wherein the sleeve is fabricated of acetal resin.

6. Apparatus according to claim 1 wherein the axle mounting means includes a screw engaged axially of the axle andextending awayfrom the axle other end.

V 7 References Cited' UNITED STATES PATENTS 2,665,521' 1/1954 Ford. i j 3,019,462 2/1962" Nash et al. -1s '1.7 3,074,087 r 1/ 963 Drennan m 1s .1.7

FOREIGN PATENTS f 7os,ss9 5/1954 GreatjBritain. EDWARDL. ROBERTS-,-Primary Examiner. 

